Any permanently or temporarily located concrete plant that
accomplishes wet batching, dry batching, or central mixing, and
operates in compliance with the following conditions of this
section is exempt. For purposes of this section, a temporarily
located concrete facility is one that occupies a designated site
for not more than 180 consecutive days or supplies concrete for a
single public works project or for the same contractor for related
project segments, but not other unrelated projects.

(1) All stockpiles shall be sprinkled with water and/or
dust-suppressant chemicals as necessary to achieve maximum control
of dust emissions. The stockpile sprinkler system shall be operable
at all times.

(2) A mechanism shall be installed on each bulk storage silo
to warn operators when the silo is full.

(3) All permanent in-plant roads (batch truck and material
delivery truck roads) shall be paved with a cohesive hard surface
that can be repeatedly swept, washed, and maintained intact and
cleaned as necessary to achieve maximum control of dust emissions.
All batch trucks and material delivery trucks shall remain on a
paved surface when entering, conducting primary functions, and
leaving the property. Other areas on the property subject to
vehicle traffic shall be watered, treated with dust-suppressant
chemicals, oiled, or paved and cleaned as necessary to achieve
maximum control of dust emissions.

(4) The cement weigh hopper shall be vented to its own fabric
filter or the central collection system specified in paragraph (6)
of this section.

(5) All bulk storage silos shall be equipped with fabric
filter(s) having a maximum filtering velocity of 4.0 feet per
minute (ft/min) with mechanical cleaning or 7.0 ft/min with
automatic air cleaning or shall be vented to the central collection
system specified in paragraph (6) of this section.

(6) The dust emissions at the batch drop point (drum feed for
central mix plants) shall be controlled by a shroud or other pickup
device delivering a minimum of 4,000 actual cubic feet per minute
of air to a fabric filter with automatic air cleaning and a 7.0
ft/min maximum filtering velocity, or automatic sequenced
mechanical cleaning (not manually activated) and a 5.25 ft/min
maximum filtering velocity.

(7) Unless the facility is to be located temporarily in or
contiguous to the right-of-way of a public works project, public
notice and opportunity for public hearing, as specified in §
106.5 of this title (relating to Public Notice), must be published
and documentation provided to the commission. A temporarily located
plant exempt from public notice may provide concrete for the same
contractor for project segments with the same governmental entity,
but may not produce concrete for other unrelated projects or other
governmental entities.

(8) Spillage of cement and fly ash used in the batch shall be
cleaned up immediately and contained or dampened so that dust
emissions from wind erosion and/or vehicle traffic are minimized.

(9) All open-bodied vehicles transporting material from a dry
batch plant to the paving mixer(s) shall be loaded with a final
layer of wet sand and/or the truck shall be covered with a tarp to
reduce the emissions of dust to the minimum level possible under
existing conditions.

(10) Before construction of the facility begins, written site
approval shall be received from the executive director and the
facility shall be registered with the commission's Office of Air
Quality in Austin using Form PI-7, including a current Table 20.

106.202 Temporary Concrete
Batch Plants (Previously SE 93)

Any temporarily located concrete facility that accomplishes
wet batching, dry batching, or central mixing and operates
according to the following conditions of this section is exempt.
For purposes of this section, a temporarily located concrete
facility is one that occupies a designated site for not more than
180 consecutive days or supplies concrete for a single public works
project or for the same contractor for related project segments,
but not other unrelated projects.

(1) All bulk storage silos, including auxiliary bulk storage
trailers (pigs), shall be equipped with fabric filter(s) having a
maximum filtering velocity of 4.0 feet per minute (ft/min) with
mechanical cleaning or 7.0 ft/min with automatic air cleaning or
are vented to the central collection system specified in paragraph
(6) of this section.

(2) The cement weigh hopper shall be vented to a control
device which eliminates visible emissions or vented inside the
charging hopper of the transit mix truck if controlled by a suction
shroud.

(3) A visible and/or audible warning mechanism shall be
installed on each silo or auxiliary bulk storage trailer to warn
operators that the silo or trailer (pig) is full.

(4) All in-plant roads (batch truck and material delivery
truck roads) and areas between stockpiles and conveyor hoppers
shall be watered, treated with dust-suppressant chemicals, oiled,
or paved with a cohesive hard surface that can be repeatedly swept,
washed, and maintained intact and cleaned as necessary to achieve
maximum control of dust emissions.

(5) All stockpiles shall be sprinkled with water and/or
dust-suppressant chemicals as necessary to achieve maximum control
of dust emissions. An operable stockpile watering system shall be
on-site at all times.

(6) Loading of rotary mix trucks at wet batch plants shall be
through a discharge spout equipped with a water fog ring having
low-velocity fog nozzles spaced to create a continuous fog curtain
that controls dust emissions, or through a suction shroud which is
vented to a central collection system with a minimum of 4,000
actual cubic feet per minute (acfm) of air to a fabric filter with
air cleaning and a 7.0 ft/min maximum filtering velocity or
automatic sequenced mechanical cleaning and a 5.25 ft/min maximum
filtering velocity.

(7) Dust emissions from the loading of open-bodied trucks at
the batch drop point of dry batch plants, or dust emissions from
the drum feed for central mix plants shall be controlled by a
suction shroud which is vented to a central collection system with
a minimum of 4,000 acfm of air to a fabric filter with air cleaning
and a 7.0 ft/min maximum filtering velocity or automatic sequenced
mechanical cleaning (not manually activated) and a 5.25 ft/min
maximum filtering velocity. Suction shrouds at dry batch plants
shall be used for closure over the receiving vehicle compartment or
bed.

(8) Spillage of cement and fly ash used in the batch shall be
cleaned up immediately and contained or dampened so that dust
emissions from wind erosion and/or vehicle traffic are minimized.

(9) The facility (including associated stationary equipment
and stockpiles) shall be located at least 300 feet from any
recreational area, school, residence, or other structure not
occupied or used solely by the owner of the property upon which the
facility is located. This distance limitation does not apply to
structures within the boundaries of the project for which the
facility is to pour concrete when the facility is located on or
contiguous to the project.

(10) Unless the facility is to be located temporarily in or
contiguous to the right-of-way of a public works project, public
notice and opportunity for public hearing, as specified in §
106.5 of this title (relating to Public Notice), must be published
and documentation provided to the commission. The temporarily
located plant exempt from public notice may provide concrete for
the same contractor for project segments with the same governmental
entity, but may not produce concrete for other unrelated projects
or other governmental entities.

(11) All open-bodied vehicles transporting material from a dry
batch plant to the paving mixer(s) shall be loaded with a final
layer of wet sand and/or the truck shall be covered with a tarp to
reduce the emissions of dust to the minimum level possible under
existing conditions.

(12) Before construction of the facility begins, written site
approval shall be received from the executive director and the
facility shall be registered with the commission's Office of Air
Quality in Austin using Form PI-7, including a current Table 20.
The current Table 20 shall be on file at each plant site.

(13) The appropriate regional office and local air pollution
agency shall be notified when the plant changes location and prior
to starting operations at each plant site.

106.203 Specialty Batch
Plants (Previously SE 117)

Any specialty wet batch, concrete, mortar, grout mixing, or
pre-cast concrete products plant that operates according to the
following conditions of this section is exempt.

(2) All stockpiles are sprinkled with water and/or chemicals
as necessary to achieve maximum control of dust emissions.

(3) Dust emissions at the batch mixer feed shall be controlled
by a water spray device which eliminates visible emissions, or a
pickup device delivering air to a fabric filter with automatic air
cleaning and a 7.0 feet per minute (ft/min) maximum filtering
velocity, or automatic sequenced mechanical cleaning and a 5.25
ft/min maximum filtering velocity, or the entire mixing operation
is conducted inside the enclosed process building such that no
visible emissions from the building occur during mixing activities,
or the batch mixer feed is enclosed such that no visible emissions
occur.

(4) Fabric filter(s) with a maximum filtering velocity of 4.0
ft/min with an acceptable method of cleaning shall be installed on
each storage silo or the silo shall be vented to the control
collection system.

(5) A visible and/or audible warning mechanism shall be
installed on each silo for warning operators that the silo is full,
so that it will not be overloaded at any time.

(6) All permanent in-plant roads (batch truck and material
delivery truck roads) are oiled or paved and cleaned as necessary
to achieve maximum control of dust emissions. Other areas on the
property subject to vehicle traffic shall be oiled or sprinkled
with water as necessary to achieve maximum control of dust
emissions.

(7) The transfer of cement from the storage silo(s) shall be
handled through closed conveying systems with no visible fugitive
emissions.

(8) The cement weigh hopper shall be vented to a control
device which eliminates visible emissions, or shall be vented
inside the batch mixer.

(9) Good housekeeping measures shall be maintained at all
times.

(10) Before construction of the facility begins, written site
approval is received from the executive director and the facility
shall be registered with the commission's Office of Air Quality in
Austin using Form PI-7, including a current Table 20.

(11) Unless the plant is to be located temporarily in the
right-of-way of a public works project, public notice and
opportunity for public hearing, as specified in § 106.5 of
this title (relating to Public Notice), has been published and
documentation thereof has been provided to the commission.